Since the advent of rechargeable batteries, different types of battery chargers have become available for recharging the batteries. Unfortunately, many of the conventional battery chargers which are commercially available do not readily permit convenient use and operation. For example, many conventional chargers require the rechargeable batteries to be removed from the product and inserted into the charger before the batteries can be recharged. After recharging, the batteries must then be removed from the charger and reinserted back into the product.
To overcome the inconvenience of using conventional battery chargers which require the batteries to be removed from the product to permit recharging, products have now evolved which enable the batteries for the product to be recharged while the batteries are still contained within the product. For this purpose, electrical terminal connections are provided on the products which permit the products to be electrically connected to a charger apparatus so that the batteries of the product can be recharged without any need to remove the batteries from the product. To effect recharging of the batteries, the product is simply mounted onto the battery charger. After the recharging is complete, the product can be removed from the battery charger with re-energized batteries.
In the flashlight industry, battery chargers have been developed which enable the batteries of a flashlight to be recharged while still contained within the flashlight. To permit the batteries of a flashlight to be recharged without causing damage to the batteries, charging circuits must be utilized to convert a power supply signal, such as an A.C. signal from a conventional wall outlet, or a D.C. signal from an automobile battery, to a charging signal having predetermined parameters to effect safe recharging of the batteries. In some of the conventional systems, the necessary charging circuit is contained within the flashlight itself rather than in a separate holder. One of the drawbacks with locating the charging circuit in the flashlight, however, is that the manufacturing and production costs for each flashlight are significantly increased. Additionally, the versatility of recharging the flashlight is also restricted since different charging circuits are required for different types of power supplies. For example, one type of charging circuit is required when the batteries are to be recharged from an A.C. power source, such as a conventional wall outlet in a residence, and another type of charging circuit is required when the batteries are to be recharged from a D.C. power source, such as a car battery. Consequently, if one type of charging circuit is employed in the flashlight, recharging of the flashlight from the other types of power sources cannot be effected.
In other conventional charger arrangements, various components of the charging circuit are contained within a special holder for the flashlight. However, when this type of conventional charger is used with an A.C. power source, such as a conventional wall outlet, the requisite transformer for reducing the A.C. voltage from the power source to the desired magnitude is conventionally located externally of the flashlight holder. Typically, the transformer is incorporated within an assembly for plugging into the wall outlet. As a result, one casing is required to house the transformer within the plug assembly at the wall outlet and a separate casing is required to house the remaining components of the charging circuit within the flashlight holder. Not only are manufacturing and assembly costs relatively high because of the requirement for dual casings, but this type of charger is not always convenient to use. Since furniture or other equipment is often placed or positioned in front of wall outlets, thereby partially blocking or obscuring the wall outlets, sufficient space or clearance is not always available to enable a plug assembly incorporating a transformer to be plugged into such outlets. Even when the outlets are not directly blocked or obscured, it is often necessary to snake the plug or plug assembly behind furniture or other equipment while en route to an otherwise unobscured outlet. Unless sufficient clearance is provided for a plug assembly incorporating a transformer along the entire route to the outlet, connection with the wall outlet is not possible.
In accordance with the present invention, a flashlight battery charger is provided which overcomes many of the problems associated with conventional flashlight battery chargers. According to the present invention, an extremely compact and highly versatile charging unit is provided for use with A.C. power sources. The compact charging unit is reliable in operation and is economical to manufacture and assemble.